Thursday, 13 December 2007

OllyHeapTrace is a plugin for OllyDbg (version 1.10) to trace the heap operations being performed by a process. It will monitor heap allocations and frees for multiple heaps, as well as operations such as creating or destroying heaps and reallocations. All parameters as well as return values are recorded and the trace is highlighted with a unique colour for each heap being traced.

The primary purpose of this plugin is to aid in the debugging of heap overflows where you wish to be able to control the heap layout to overwrite a specific structure such as a chunk header, critical section structure or some application specific data. By tracing the heap operations performed during actions you can control (for example opening a connection, sending a packet, closing a connection) you can begin to predict the heap operations and thus control the heap layout.